Obtaining naphtha from natural gas.



G. M. SAYBOLT. OBTAINING NAPHTHA PROM NATURAL GAS.

APPLICATION ILED SEPT. 1, 1906.

Patented Apr. 18, 1911.

Z SHEETS-SHEET 1.

G. M. SAYBOLT. OBTAINING NAP'HTHA FROM NATURAL GAS.

APPLICA 0N 98999270 T1 FILED SEPT 1 190e Patented Apr. 18 1911.

2 SHEETS-SHEET 2.

D Y D wi #manna To all whom it may concern:

-NICrED sTA'rEs PATENT oEEicE.

GEORGE M. sAYBoL'r; 0E JERSEY CITY, NEW JEnsEY, Assm'Noa lro 4smattutina 01E coMrANY, -E B'AYoNNE, NEW JERSEY, A coEPonATIoN or NEW JERSEY.

OTAINING NAPHTHA FROM NATURAL GAS.

Be it known that L-GEORGE M. SAYBOLT, a citizen ofthe UnitedStates, residing at Jersey City, in the county of Hudson'and State of New Jersey, have invented new and useful Improvements in Obtaining Naphtha from Natural Gas, of which the following is a specification.

This invention relates to the obtainment Aof naphtha from combustible'gas of natural origin and underground source, which gas is obtainable .b means of'wells sunk into the ground tot e proper horizonand is capable of usci as fuel. Natural gas wells sometimes do and sometimes 'do not yield loil' also. In-oil-yielding gas wells (or to state the matter conversely, in gas-yielding oil wells) ,the natural gas may. rise with the oil; or a separation between them may take place underground. From the wells the gas' is'piped to the places of consumption, which may be lon er or shorter distances away. This natura gas is and long has been obtained and used in enormous quantities.

' One single well for example has been known to yield thirty-six millions of cubic feet of gas in twenty-four -consecutive hours. While therefore the naphtha exists in the gas in the form of 4vapors under small tension and consequently in an attenuated c`ondition and `whileit composes only a small proportion of thegas, atleast ordlnarily,

the amount varying inthe gas from different wells, yet in the aggregate a large quantity of naphtha is dail burned as fuel, along with those combustib e constituents' of natural gas (hereinafter referred to as the .-lightercombustible .constituents of the gas) which are gaseous at atmos heric'pressure and temperature. Naphtha 1s volatile; but

. it isliquid at atmospheric pressure and temperature, sayifteen pounds to the'square inch,. and o Fahrenheit, or thereabout. 'It

maybe delined -generally as including all hydrocarbons, and each of them, which are liquid at atmospheric pressure and temperature, and which havelower-boilin points than the normal hydrocarbons of urning oil (kerosene). It exists-invapor form'in natural gas'byreason of its association with the other' constituents thereof.

Thereexists, and for. some years back has existed, a great demand for naphtha. It is Imainly 'obtained' from petroleum; and the crude oils from fields developed in recent Specication of Letters Patent. `Application filed September 1, 1966. Serial No, 332,988.

years contain it in less from each otherv of the pipes lead' from wells a to the 4main line b, which extends beyond the 'drawing to Patented Apr. 1s, i911.

proportion `than does Pennsylvania oil. some years has been highly important to enlarge the available supply of naphtha. The

.present invention has vthis object in view.

It 1 s therefore, and for In accordance with this invention, natural gas, as defined above, is subjectedto an absorbent menstruum; bythe aid of this menstruum 'a separation is effected of the naph-` tha from the lighter combustible constituents of the natural gas; and the absorbed naphtha is afterward separated from the menstruum and is recovered apart therefrom in the form of `a liquid product; or, if the product of,thenaphtha absorbing operation without separation of the absorbed naphtha and the vabsorbent menstruum from each other should be desired, then in such case the said product, or so much of it as should be desired, would be oollectedand the separation naphtha and the menstruum would be dispensed with..

The naphtha obtained 'from natural -gas in accordance with the invention can be utllized for the ordinary purposes of naphtha of similar gravity, with or withoutbeing further operated upon, in any appropriate way according to the case. When necessary or'` desired it can, for example, be subjected to .$5

treatment with sulfuric acid and alkali; and? -it can be fractionated into liquids of dif;f

ferent gravities, forvarious purposes,

In the accompanying drawings, Figure i is a diagram in plan view of apparatus in accordance with the invention having a still to separate the naphtha from the menstruum Fig. 2 is a diagram in vertical section andelevation of the main portion of the same apparatus; Fig. 3 is a diagram in vertical section and elevation, illustrating another form of means for se larating naphtha and menstruum` from eac other; Fig. 4 is a sul diagram in vertical Asection and elevation,

exhibiting 'another form of still; Fig. 5 is .-a diagram in vertical section and elevation,

and Figs. Gand 7 are diagrams in .plan and in vertical section and elevation, respec.d tively, illustrating other forms of means' for absorbing the naphtha ofnatural gas; and Fig. 8 is a diagram in vertical section and elevation of another form of naphtha absorbing and naphtha distillingmeans.

Referring to Figs. 1 and 2, gas conveying gas places of consumption. Gas holders in the .Y

main gas line, or in the tributary lines leading from the wells .a can be used'or not as may be preferred, and if used they can be placed wherever ldesired. Sometimes the well pressure may suiice to effect the conveyance of the natural gas through the line b insufficient quantitiesv to meet the wants of'consumers; but in order 'that eXtra pressure may be applied to the gas when' desired so as to force it through the line a pump c is shown. It has appropriate pipe connections with the line b; and valves are indicated in said connections and in the line for controlling the flow of gas through the same. The branch d leads from the gas line bte the means forsubjecting the natural vgas to the naphtha absorbing menstruum and for enabling a separation'ofnaphtha from lighter combustible constituents of the gas to be eli'ected by the aid of said men- 'l struum. Said Abranch Z thus serves to con- E neet said means with the underground sources'of the gas, which sources are tapped by the wells a.

The separation of the naphtha by the aid of the absorbent menstruum Jfrom atleast the main body of the lighter combustible constitutents of the as is best effected in the absorbing operation; but itis believed that it might possibly be effected by the aid of the absorbent menstruum afterward; say

for example, by absorbing the main body of said lighter combustible constituents along with the naphtha and then allowing the fornier to escape while the naphtha is held by the absorbent menstruum.

Heretofore appliances of'many kinds have devised forbringing gas intov contact with 'other material with a view of separat- *ing one or more of its constituents from therest of the gas. The means of the present irlagention for subjecting natural gas to naphtha absorbing menstruuinmay include` generally such appliances of any desired kind ibut by way of example in Figs. 1 and 2, the `means shown contain appliances for showering a liquid naphtha absorbing menstruum through the natural gas. The absorbers e consist each of a tower filled with pieces of solid material, as broken stone for example, or pieces of coke, or the like.

Natural gas from branch d lenters atthe botmenstruuminlet (rose f) of each absorber I is shown a short column which contains pieces of solidmaterial and through which v the outflowing gas passes. It serves to prevent'inenstruuni being carried over mechanically by the iiow of gas. Naphtha, with or without lighter comlbustible constituents ofthe gas, is absorbed by the menstruum in each ofthe absorbers c; and by arranging the appliances whereby the pressure and temperature of the gas are controlled in such manner that the pressure inthe absorbersat the therein eXistin teinperature is insuiicient to effect the a sorption of the mainbody of the lighter com- -bust-ible constituents of the gas, the main body of the gas will return by branch z" to the line b. j

'The absorbers e are arranged to receive a previously produced menstruum. The latter, supplied from any suitable source, can be delivered'tlirough the pipes h connected with the roses f of the absorbers. As shown,

the `tank is for receiving the menstruum from say either or both the pipes 7c, Z; and it can be withdrawn from tank y' by pipe m for delivery to the absorbers; or the menstruum can also be supplied direct from pipe n, without entering the tank j.

The ratio in which the menstruum and the natural gas are respectively supplied to the absorbers is governed by the valves in the gas supply branch d 'and the menstruum supply pipes m, n, through whichever the menstruum' supply may be taken. The volume of the natural gas supply should be many times that of the menstruum, in order thatv the menstruum may absorb a considerable content of naphtha; but the yextent of the .absorption can be regulated Vaccording to the wishes of the operator, within the absorbing capacity of the menstruum employed under the conditions of its employment. .By circulatingthe menstruum by pumps g through the ab CJI sorbers e, the same particles of menstruum can be brought as much as desired into contact with natural gas. 'The circulation of the menstruum and its continuous renewal through pipes m2, n, or one of them, and the arrangement generally of the absorbers e allow an uninterrupted flow of the natural gas from line b. by way of thebranch d, absorbers e, and branch z', back to line b.

Whenthe natural gas is delivered from the wells a under a satisfactory condition of pressure and temperature, s uch condition being oftentimes more favorable lto naph-' tha absorption than is the condition of atmospheric pressure and temperature, it is preferred to subject the natural gas at its natural condition` of pressure and temperature to the absorbent menstruum. Thus the expense of compression and cooling (or of cooling, if the pressure should not be -iii etape? p creased) 'is avoided. The branches d, i, are

y gas at such' natural condition shown arranged to receive and to return the (barring changes due to frictionv and the like), they being shown connected with gas line b between the wells a and the line connections of pump 0. For producing artificially a condition more favorable to absorption than that available naturally, a pump p is' shown for increasing the pressure, and a cooler g for reducing the temperature of the compressed gas, or (if compression should not l be desired) of the uncompressed gas.

Instead of subjecting the natural gas l in a single stream tothe action of the absorbent menstruum, the gas supply is advantageously divided into a number of parallel streams;- and the absorbingvessels e, which each ofy them confine and convey such a stream, are

of comparatively small diameter. They are thus better able to withstand Iinternal superatmospheric ressure, than would be an absorber of su cient diameter to carry singly the Whole supply of gas. As shown, two absorbers e are represented in parallel; but in practice as many of them would be employed in parallel as should be thought necessary or expedient.

.In order morethoroughly to extract the naphtha from the gas and at the same time n to obtain va larger content of naphtha -for the menstruum, the natural gas Vfirst meets menstruun containing more naphtha and afterward ythat containing not so much. To

accomplish this, the absorbers e are connected in series, the' gas from the top of the first absorber e of a series passing bypipe 1' tothe bottom .of the absorber next in series,-

and the menstruum .which 'has been circulated in one absorber being delivered by pipe s to the preceding absorber of the series. Absorbers arranged in two parallel series of two in each series are shown; but the number in series can in practice be as large as may be considered necessary or expedient; and there may be as many series in parallel as may be desired or a single series arrangement can be used, if that. should befpre- Iferre'd. As "shown, `the fresh menstruum fror plpes m, n., or onevof them, enters' the the pump g appropriate to the-last absorbers of both series; and inl connection with inenstruum which flows from the bottoms of said 4roses f at the. ends f absorbers it is delivered into thosel absorbers 'near their tops through .the corresponding branches of the cirylating pipe h. and the f said branches* SomeV of the n aphtha` containing menstruumfrom the last mentioned circulating pipe lt is de'- livered by pipe .sato the circulating systei'ns.

of the preceding absxirbers in .bothlseries and 1s mmgled with the menstruum ofiarger u per parts of these absorbers. By opening pipe w, the'fresh menstrum can-be supplied- Y- supply branch fl.

without distinction to all the absorbers. In

that case also theV natural gas would first meet menstruum containing more and afterward that containingless naphtha; for the menstruum would begin to absorb -naphtha immediately on its entrance into each absorber and would continue to do so during its -descent therein; and in the absorber which should rst receive the natural gas it would absorb the most naphtha lbefore reachingthe bottom' (where the gas enters) so that the body of menstruuin in this absorber Would hold more naphtha in absorption therein than*v would the body of menstruum in a 'succeeding absorber in Ithe series; although there might be no difierence between them in naphtha content when discharged by the respective roses f. .l )Vith pipe a: open one pump g would suffice to circulate the menstruum of all the absorbers; for the open pipewould put the bottoms of all the absorbers in communication with each other; While the openpipe s establishes communication between the upper parts of all. l

The menstruum, containing as much naph- Vtha as it can absorb underl the conditions of the case, is carried 'away by the pipept; from which it can pass by pipe u. into tank fv, to be thence delivered by pump a to one or other or to both of the pipes 3, fw; or it can pass from pipe t direct to one or other or to both of' said pipes 3', w, Without entering the tank fu.v The valves'i pipes l, m, n, t, vl,

Ican be adjustedl to maintain a suiicientlyuniform quantity of liquid in the absorbeI'S 6.

Whether the naphtha containing meni struum from the absorbers e should'be al lowed to enter the tank fv, or should be sent direct to'one or other or to both of pipes 3,

i fw, it'can be held under the pressure-existing in the absorbers; or the pressure can be reduced Ain passing an appropriate valveor valves. )Vithout reduction of pressure, the tank 'o would serve for a temporary storage;

with reduced. pressure therein, it would serve, as shown, ieither or bot-h the purposes otA temporary vstorage and of separating. from the naphtha'enriched menstruum such lighter combustible constituents of 'the ,gas as mightlbe absorbed with the naphtha in the absorbers and be liberated on the reduction of pressure. For this latter purpose,

it is shown provided with a gas pump y for withdrawing the gaseous constituents from the tank v and delivering the same either into the gas returnbranch z' or into the gas The latter connection would be opened incase it should'be -found that the gas should contain enough naphtha torenderits return to the absorbers worth while. l

If desired, the naphtha containing luen- Vstruum from tank -vcan be returned to the absorbers e'by means of pump a andvpipe Such return might sometimes be useful, in case the menstruum should not be .suilif ciently charged with naphtha. If the condition in absorbers' e should be such that not only the naphtha but also the main body of y the lighter constituents should be absorbed,

A.Which might be possible under extreme pressure and low temperature inthe absorbers, but Which is not considered advantageous, then in such case the separation of the naphtha enriched menstruum might take place in the tank fv, by maintaining therein a condition of pressure and temperature less favorable to absorption; so that the menstruum on entering tank o would liberatethe main, vbody of the lighter combustible constituents of the gas, Which Would be Withdrawn therefrom by pump y. The tank en could be at any desired distance from the absorbers; but in some cases at least it would best be in proximity to the absorbers e; and it is so shown.

The pipes 3, w, are respectively provided, the pipe 3 for allowing the menstruum hol d ing iti-absorption therein natural gas naph-` tha separated from at least the main body of` combustible constituents of the gas to be Withdrawn Without recovery of the naphtha.

from the menstruum, the pipe fw for conveyance of the said menstruum to means for recovering thenaphtha therefrom. A

As lshown in Figs. 1 and 2, the ipe lw leads to the coils or pipes of a'heat exc anger 4, in which the temperature of the naphthal enriched menstruum is raised by exchange of heat with the separated menstruum returning by pipe 5 from the bottom ofthe continuous steam still 6, Which constitutes the means shown in these` figures forseparating the naphtha and the absorbent menstruum from each other. The pipe 7 delivers the heated product from the exchanger to' of the column located above the inlet of the naphtha enriched menstruum and containing pieces of solid material; and then -they pass by pipe 12 to thecondenser 13 wherein condensation takes place, the naphtha being re-4 duced ordinarily to "a product liquid at atmospheric pressure and temperature. A

trap 14 at kthev outlet vof the condenser is' ,shown for separating the naphtha and the VWater from each other by settling and defc'ant'ationin the ,f 'known manner. Unconaaaozv l densed gas Which'may accompany the Water and naphtha escapes by the pipe 15 and is disposed of as may be desired. "It may, for

example, be piped to a place of consumption on the premises', say -by pipe 416 to the fur-A nace of steam boiler 9; or it may be sent to the gas line b, say by Way of pump 17, pipe ,18,'and return gas main i; or it may be disposedof otherwise. At 19 is shown a storlage tank for the naphtha, which is supplied thereto from trap 14 by Way of pipe 20.

The menstruum fromyvhich the naphthahas been separated would best, in most cases,

it .is believed, be utilized by subjecting a fresh supply of natural gas thereto. As shown itis conducted from the still 6 to the space around the coils or pipes of exchanger Llby pump 5 and pipe 5; and thence it 'passes by pipe 21 to a cooler 22, in Which -its temperature is further reduced before it is delivered by pipe fn, to the 'circulating systems of the absorbers 6. But a menstruum which it is desired to utilize either by Working up into one or more products or by `applying to some useful purpose Without lbeing further operated upon, or which it maybe desired to dispose of Without utiliza# tion should such'a case ever arise), can be Withdrawn by pipe 23. .It could also be run by pipe Z into the tank -j and then be Withdravvntherefrom. The means for separating the naphtha and the menstruum from each other can be placed at any* desired distance from the naphthav absorbing means; but in some cases atleast theyvvouldbest be in proximity thereto and they are so shown. l Instead of taking the supply of natural gas from Which naphtha is to be obtained from the gas line b in advance of the pump 0, it can be taken therefrom after it has been compressed by the latter, the heat generated by the compression in pumpe being removed before the' gas is subjected to the naphtha 'absorbing menstruum. By placing the gas supply branch and the return gas branch at a suitable distance, as indicated for pipes 24, 25, at the right of Fig. 1, the heat Will be removed Without expense by conduction from the Walls of the gas line b to the surrounding air or ground.

In Fig. 3, in'place of a still .for separating the naphtha and the absorbent Vmenstruum from each other, the means consist of a mixer 26 and ausettling and decanting vessel 27. The naphtha enriched menstruum `enters the mixer 26 frompipe w (which may be taken to be a continuation of the sim1- larly lettered pipe of Figs. 1: and 2) While a medium capable of parting the naphtha and the menstruum entersthe pipe 28. l The sel 27. Here separation takes-*place by gravity; the heavier liquid flowing olf by pipe 30; and the li hter escaping -by pipe i 31. Assuming that t e naphtha composes the lighter liquid, whilea solution of thelabsorbent menstruum and the separating medium compose the heavier, the said pipes 30, 31 are noted as leading the latter to a tank and the formerV to a still, which may be of any suitable description, for recovering the absorbent menstruum. IfA a steam still should be unsuitable therefor, a dry heat still would be used; and itmay be used in any event. In Fig. 4 a form ofsuch still is represented; although other forms can be used. Such a dry heat still could be used in place of the steam still of Figs. 1 and 2, as'

well as in connection with the means of F ig. 3 for separating the naphthaand the menstruum from eachother; and therefore theV pipe which delivers thereto the liquid to be distilled is marked fw or 30, the former being the still feed of Figs. 1 and 2, and the latter the still feed of Fig. 3. The still itself is in the form of a column filled with pieces of solid material in its upper portion and p rovided with a close steam coilI 32 in the bot- .tom part to supply the heat required to effect the distillation. The pump 33 and pipe 34 are for discharging the residual liquid. If naphtha enriched menstruum should be fed to the still, the menstruum' would naturally be less volatile, and would fconstitute the residual liquid; and the pump 33 and pipe 34 wouldl then correspondv with struum. The plpes d, ,'represent the similarly lettered gas supplyand 4'gas returnthose marked 5, 51Av in Figs. 1 and 2. If a solution of menstruum and the medium for separating naphtha'therefrom should be fed vto the still, the absorbing menstruum (if the more volatile)v`would`pass 0H to the condenser and be recovered as condensate for reuse in absorbing naphtha from natural gas. If it'should not be suliiciently freed from the naphtha separating medium by onev distillation, repeated distillations can be resorted to. Andl so also they can be 'resorted to if necessary or desired for separating the naphtha and the absorbentmenstruum; only if the menstruum should be returned for reuse in theabsorbers the presence' of naphtha below saturation 'would only limit and not destroy absorbent capacity.

VIn Fig. 5 a form of naphtha absorbing means is shown in which the natural gas bubbles up through pools of absorbent menbranches of Fig. 1. The vessels 35 of comparatively small diameter, are each provided with a gas inlet pipe 36, connected 'with the branch d' and terminating near the bottom of its vessel in` a perforated-section or rose. Each vessel also hasa gas escape pipe 37 .at the top leading to. the return branch z and also having a valved pipe connection 38 with the gas inlet pipe of the absorbing vessel 35 next adjacent to it on one side. 7lfhis arrangement of pipes allows the vessels 35 to be connected in parallel or in series or in parallel series with reference to the flow of gas from the supply branch d to the return branch z'. The vessels have each a valved pipe connectionat the,top with thel absorbent supply pipe @,Which represents thesimilarly lettered ,pipe of Fig. 1, and at the bottom with the pipe t which serves for drawing oft' the naphtha enriched menstruum and represents the similarly'lettered pipe of 4Fig.A l. Each vessel also has a valved pipe 39` connecting the upper part of its menstruum holding space with the lower part of the menstruum holding space of the vessel next adjacent thereto and provided also with a valved branch leading to the draw off pipe. t. lBy this arrangement of liquid conveying pipes, the fresh menstruum can'be supplied to, and the enriched menstruum be drawn off from, each vessel individually; or the vessels can receive the menstruum in series, the first of the series ref ceiving the fresh menstruum from pipe `n and the last delivering the enriched menstruum tothe draw-off t. The vessels can be disposed in parallel series; since each vessel has the' same, pipel connections; and any vessel not an lntermedla'te member of a series can becut out.l Five vessels are repref sented; but as many as may be thought necessary or expedient may be employed. As' suming that all ive were to constitute. oneseries, in that case the menstruum might be A admitted in a continuous manner to the ves'- sel at the right 'and the natural gas in an uninterrupted stream into the vessel at the left. Or the pipes 39 betweenv the vessels could be closed, Vand each vessel in turn could be cut out of the gas current, be filled with menstruum from pipe n, and be discharged of its liquidcontents intopipe t without interrupting the continuityof How of the natural-gas through the series' ofvessels.` Or the pipes 39 being closed, the menstruum, could be supplied in a continuous manner to each of the vesselsl directly from the pipe n, the gas continuing to flow in series. Also the gas might be admitted to each vessel direct from the supply branch d, (the vessels. being in parallel between the branches d, z',) and the menstruum could besupplied direct to. each vessel in a continuous manner or at 'Y intervals, each vessel being cutout in turn to be emptied andreilled tothe proper height,

say about half full. y

`In Fig. 6 the naphtha .of the natural gas from `line b is absorbed by a menst-ruumas it flows in a pipe line, the gas bein forced by pump 40 into the line 41, throng which the absorbent menstruum is forced by pump 42. The condition'ofpressure and temperature in the line 41 beyond the junction therewith of4 the branch' connection from line b would best be such that the naphtha vapors would be absorbedvas completely as prac. ticable by the menstruum, while the main body at least of the lighter combustible constituents of the gas would be unabsorbed.-

A separation of the naphtha and such constituents would thus take place in the pipe line itself. When -the separator 43 is reached, the lighter combustible Constituents of the gas can be withdrawn by pipe 44,

while pump 45 and pipe 46 deliver the enriched menstruum to a storagetank or to means for separating the naphtha and the menstruum from each other. -The pipe line. pressure can be retained in the separator 43; i ut it can be reduced by proper setting of a .valve in the pipe line 41, and the pressure on thenaphtha enriched'menstruum would best-be reduced previousto-the separation of thenaphtha and the menstruum .from each other, unless it should be desired to obtain the naphtha as a productrequiring at Yleast the pipe line pressure to ret-ain itin a liquid condition. The pressure in the pipe line can be `obtained by adjustment of the speed and power of the pumps 40, 42, and

by-proper'throttling of the .pipe line fluids at lthe end of the line, say by the valve on the pipe line 41 near the separator 43'. The

respective volumes of the natural gas and `the menstruum can be regulated asdesired;

but unless the volume 'of the former many times exceeds that of the latter, the enrichmentof the menstruum will be only meager.

.Ila

The adjustment of the relative s eeds of pumps 40, 42, will regulate the rat-1o of the -gas to the menstruum.

Fig. 7 illustrates a plan for absorbing the htha inthe natura gas as itrises in the l a. The menstruum is delivered through thepipe 47 into-the rising gas. If the gas "posits the menstruum carried thereby;

current is strong enough to carry along the showered menstruum in suspension in the gas, the pipe 47 would best deliver the menstruum into the lower n part of the well: if the menstruum should fall through the gas, notwithstanding the current, the pipe 47 might advantageously be arranged to discharge the menstruum nearer the top of the well. Its koutlet can be set at any desired level. As shown, there is a line of tubing 48 for returningthe menstruum from the bottom of the well; and the gas outlet 49 dischargesinto a separator 50 in which it dewhile the gas then passes on by pipe 51. They menstruum from the bottom of the-well andthat from the separator are delivered to an appropriate tank or tanks or to means for separating the naphtha and the menstruum from each other. In the separator 50, perfo- `4`rated division plates 52 are shown to aid in separating liquld in suspension from the gas. Instead of eEecting the absorption of the I naphtha in the menstruum and the separa- -tion-of the absorbed naphtha'and `the men- .struum from each other in separate vessels,

the

the two operations can be performed in l secties? f' same vessels. Fig. 8 illustrates an arrangement for the purpose. Many of its parts are like `corresponding parts in Fig. 5; and as they are similarly marked for reference they need not be further described. -In ad- 'dition a steam inlet pipe 53 is shown with.

which the pipe '36 of each 'vessel V54 has a valved pipe connection for injecting steam into the enriched menstruum when it isde' lsired to separate the absorbed haphtha there from; there is also shown a vapor pipe 55, with which each vessel has a valved pipe connection,- for conveying the vapors of -naphtha and water which' pass out' of the vessels during the steaming operation; and lastly there is shown on each vessel 54 a trough 56 to which thepipe 57 can deliver a cooling liquid when desired, each trough 56 being perforated below so that the cooling liquid will flow over the outer surfacesl separating the naphthaifrm the menstruum,

that is the vessel which'first receives the natural gas would have its;I gas supply shut ofl (the next vessel now becoming the 'rst to receive the natural gas) and would also have its connections with t-he adjacent vessels 54 and with the return gas branch z' closed. Said-vessel would then have its connections with the steam pipe 53 and vapor 'pipe 55 opened; and its contents would be steamed untilfthe naphtha should be eX- pelled to the desired extent. Then these last mentioned connect-ions would be closed; and the contents of Ithe vessel would be allowed to stand for the water of condensationfrom the steam to Settle, cooling liquid from trough 56' being at the same time al.

lowed to iow down over the outside of the vessel. When settled, the water would be drawn off through pipe 58; .and the iow of the cooling fluid would be continued untilv the temperature should be suitably. reduced.

Thereupon, the vessel would be connected7 aga-in in the gas receiving series, at the end at which the gas leaves the absorbing vessels. Morer than one vessel can bel cut out at the same'time, say in order to give a longer time-to each for'the distilling (or naphtha separating) and coolin operations.v

If the vessels of Fig. 8 should e connected in parallel, then one or more of them could Vhave their gas connections closed and be utilized as steam stills for separating the natural gas between the branches d and t'. f

5 The menstruum to be used in carrying on the above described operations may beany substance or composition having an appropriate affinity for the naphtha vapors and otherwise adapted to the conditions of use. If the absorbed'naphtha'is to be separated by distillation from the menstruum enriched Ithereby, it must usually be less volatile than the natural'gas naphtha to be obtained, in Aorder to enable the separation to be effected; for unless in exceptional cases liquids of the same boiling point cannot be separated by distillation. Substances, other than hydrocarbons can be used, for example, the fatty oils and their constituent acids, also amyl alcohol, and others; but hydrocarbons are considered most suitable, and especially some form of petroleum, on -account of its cheapness and abundance. Assuitable .non-petro-` leum hydrocarbons may be mentioned coal tar of gas Works, oils derived therefrom, crude oils from' distilling coal, shale or schist, and other non-petroleum bituminous substancesfor oils, products derived from such crude oils, and' turpentine oil. Petroleum in almost any of its forms less volatile than the natural gas naphtha to be obtained can be used, as maltha and more fluid crude petroleum, reduced oils, tars, vaseline, distilled loils and so on; but I have discovered that petroleum hydrocarbons with boiling points separated by a considerable temperature iuterval, say 100V degrees F. or more, from those of naphtha hydrocarbons have a greater aiiinity for naphtha than those whose boiling points are closer thereto. I believe, however, that petroleum in a form but little less volatile than natural gas naphtha Will have some absorbent capacity for t-he latter. If the absorbed naphtha is to be separated otherwise than by distillation from the menstruum enriched thereby, the menstruum .should be adapted to such separation. Ethyl alcohol sutiiciently anhydrous, acetone, mixtures of acetone and methyl alcohol, absorb naphtha and on dilution with Water part with it. They are suitable therefore for use Where Asuch mode of separation is preferred.'

If the absorbednaphtha is not to be separated from the menstruum, the latter should be adapted to 'serve in connection with the naphtha for the use to which the naphtha is to' be put. A petroleum naphtha less volatile than the natural gasnaphtha to be absorbed thereby, enriched .by such natural gas naph- ,60 tha might prove a useful product for some 1 purposes. My experience tends to show that considerable pressure or a loW temperature or both Would be neededvto efectthe absorption of natural gas naphtha in naphtha which should be 1essvolatile,'and it may be that the product would have to be held under pressure in order to retain a suitable proportion of that which should be absorbed.

I have not tried all the substances nor all the modes of working herein mentioned; but I have absorbed naphthafrom natural gas and in so doing separated it from the lighter combustibleconstituents of such gas'by caus ing the natural gas from a Well Which did not yield oil to bubble up through a body of petrole-um distillate of about 30 B. gravity and about 300 F. fire test in a 'vessel of about 12 inches in diameter under an internal pressure of about 30 pounds to the square inch abovel atmospheric' pressure and at atmospherictemperature; and I havelrecovered thev natural gas naphtha. from the menstruum by distillation and condensation. I believe that all the substances and modes of working herein mentioned will operate, and that a 'pressure of about 300 pounds to the square inch Wouldbe preferable to one of 30 pounds. A

If a sufficient supply of crude petroleum should be available, it Would be best in my opinion to use it for the absorbent menstr'uum. After the absorbing operation, carried on, say at a pressure of about 300 pounds to the square inch 'above atmospheric pressure and at about atmospheric temperature, in absorbers of the form shown in Figs. l and 2 or in Fig. 5 or in Fig. 8, and with return of the unabsorbed lighter constituents of the gas to the gas line l) (as described with reference to Fig. l), the crude petroleum enrichedy with the absorbed naphtha v could advantageously be'delivered into say tank@ of Fig. l under approximately atmos-v pheric pressure, or the pressure could be relieved in vessels 54 of Fig. 8, any lighter combustible constituents liberated at this time being Withdrawm One effect of the absorption of the naphtha is to lower the gravity of the absorbent menstruum, and by observation of the gravity of test specimens Withdrawn in the absorbing operation, or from tank fv, the conduct of thisoperation can'be regulated. After reduction of the pressure, the enriched crude petroleum can be distilled in order to separate the absorbed naphtha and the menstruum from eachother, in steam still 6 of Figs. 1 and 2 or in the dry heat still of Fig. 4, or in the absorbing vessels 54 of Fig. '8, or in any other still. By this distillation the naphtha of the crude oil, as well as that of the natural gas will be obtained, they being separated together from the residual liquid. This liquid, being the residue of the crude petroleum, would then be utilized by being Worked up into burning oil (kerosene) and other products as may be desired. lThe crude petroleum before or after the separation of naphtha therefrom could vbe piped any desired distance .to lthe geously utilize natural gas which should be piped to it with the crude petroleum, as indicated hereinabove with reference to Fig.` 6, it might Well be so piped, absorption of naphtha from the natural gas taking place I in transit. v

If a sufficient su ply of crude petroleum should not be avai able, it would be best in my opinion to employ1 a heavy petroleum oil (say the Vtar of crudel petroleumafter removal o'xthe burning oil, or'else a heavy distillate of B.,4 or heavier as the absorbent menstruum'; 'and after t e absorbing operation and the separation of the naphtha and the menstruum from each other by distillation to utilize the separated menstruum, by subjectin natural gas theretoiny order that it may a sorbnaphtha from the same.'

-The expression petroleum or hydrocar-l bon oil as specified means primarily a liquid or semi-liquid form of petroleum, which is composed 'at least largely of hydrocarbons With boiling points a long temperature interval (say an interval of about 100 degrecs F. or more) higher .than those of the principal hydrocarbons of natural gas naphtha and which may -consist of ypetroleum (or in other Words of any natural llquid Vor semiliquid bitumen) in the crude state or of a product prepared therefrom by reduction, distillation or otherwise; Ibut by extension it includes 'a liquid or scmiliquid which is not a form of petroleum but which nevertheless is `composed at leastv largely of'hydrocarbons vvith'comparativel high boiling points as just mentioned; an by extension.-

it also includes in general a liquid or semiliquidl which is less volatile than the naphtha of natural gas and is composed at least largely of hydrocarbons. -Mention herein of materials and of modiiications in procedure and in apparatus is by Way of example and is not exclusive of` other modifications Withiny the spirit of the invention.

I claim as my invention or discovery 1. The process-of obtaining naphtha from 'combustible gas of natural origin andunderl ground source of the kind supplied b means of Wells and pipe lines to cities or consumption therein, which process consistsin subjecting such gas in the requisite large amount on the way from its underground sources to its places of consumption and under a high pressure, not less than about thirty poundsl to the square inch above atmospheric pressure, to a naphtha absorbing -menstruum, and by the aid of the same under said high pressure eecting the separation in industrial quantity from said gas of a natural gas naphtha liquid at atmospheric' pressure and temperature' and applicableto the uses of petroleum naphtha of .similar volatility, substantially as described. Y

2. vThe process of obtaining naphtha from combustible gas of natural origin and under ground. source ofthe kind lsupplied by.4 means of Wells and pi sists in subjecting such gas in the requisite large amount on the- Way from its undery ground sources to its places of consumption and under a high pressure,l not.less. thanv about thirty Apounds to the `square inch above atmospheric pressure, to a naphtha absorbing menstruum, especially petroleum or h drocarbon -oil as specified,- and by the ald v lines to vcities for consumptlon therein, vv ich process conof the same under said high pressure effectin g the separation in industrial quantity from said gas of a natural'gas naphtha liquid at atmospheric pressure and temperature and applicable to the-uses of petroleum n'aphtha of similar volatility, and thenA recovering the naphtha in liquid` form from `said menstruum by distillation under a low pressure', not more than about atmospheric pressure, substantially as described. 3. The process of obtaining naphtha from combustible gas of natural origin and underground source of the kind supplied by means of Wells and pipelines to cities for consumption therein, :which process consists in subjecting such gas in tthefrequisite large amount on the Way from its underground sources to its places 'of consumption and un.

der a vhigh pressure, not less ,than about thirty pounds to the square inch above atmospheric pressure, to a naphtha absorbing menstruum by causing the gas to bubble up through pools o`f the menstruum, and by the `aid of the same under said, high pressure effecting the separation in industrial quantity from said gas of a natural gas ynaphthav liquid at atmospheric pressure and temperature and applicable to the uses of etroleum naphtha of similar volatility, su sta'ntially as described.

` In testimony whereof affix my fsign-a-i ture, in presence vof tvvo subscriblng Witnesses.

-Witnesses:

BENJ. F.- CUMMINGS, MARYA E; Drcu'son.

GEORGE M. sAYBoLT'. 'i 

